When it comes to social and environmental proposals this past year, though, one reason for the rise as a proportion of overall initiatives was that the number of executive compensation-related shareholder proposals declined. According to calculations by Proxy Monitor, compensation proposals made up just 13% of all initiatives this year, down from 28% in 2010. Says James Copland, director of the Center for Legal Policy at the Manhattan Institute, the reason was that say-on-pay regulations provided shareholders with another mechanism for voicing their opinions on executive pay.

Even so, shareholder support for the proposals definitely grew overall. "We're seeing both an increase in the number of proposals, and an increase in the level of support they're receiving," EY's Brockett says. The average social proposal received support from 21% of voters in 2011, compared with 10% in 2005, according to the E&Y report, which covered 2011 shareholder meetings held through June 30.

Moreover, the percentage of resolutions capturing support from 30% of voters -- the level at which many boards begin to take notice, according to Brockett -- skyrocketed between 2005 and 2011, climbing from a mere 2.6%, to nearly a third (31.6%), the E&Y report says.

"We used to be thrilled with single digit votes," says Andrew Behar, chief executive officer of that has introduced shareholder proposals. "Now, when we file a resolution, they (companies) come to the table."